Asteroid about to make a close shave with earth ... but how close?

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An asteroid thought to be up to 50 metres in diameter is expected to make a close shave with our planet on Saturday, although scientists are not sure just how close.

However, it is thought to be unlikely that “2013 TX68”, as it is known, will collide with the earth.

Euronews’ Jeremy Wilks spoke to a scientist at the European Space Agency, Michael Khan, an expert in asteroids and space debris.

Wilks: “To what extent does this asteroid pose a threat now?”

Khan: “The problem with this asteroid is that we don’t know much about it. We know approximately what its orbit is. We don’t even know how big it is, we know it’s somewhere between 20 and 50 metres in diameter. But we know the orbit to the extent that it allows us to say that it won’t hit the earth in March 2016 and we will have two encounters in this century and there it probably won’t hit the earth either.”

Wilks: “What would happen if an asteroid of that kind of size hit the earth?”

Khan: “This is kind of ‘iffy’. It’s likely – if it’s on the smaller end of this range of diameters – that it would just explode in the atmosphere, like the one in Chelyabinsk a few years back, over Chelyabinsk, that exploded and caused some damage but luckily no casualties. But it might conceivably hit the surface and make a hole and then you would be looking at really a real problem, damage and possibly also lots of people killed.”

Wilks: “In general, to what extent are asteroids a threat to us now?”

Khan: “Asteroids have always been a threat to the earth. If you look at the surface of the earth, it’s pockmarked with impacts. But luckily the larger the impacts are, the more damage they incurred, the less frequently they happen. So it’s not a very likely thing to happen but if a big impact happens it might have consequences that entail the end of civilisation as we know it. But that’s not a likely thing to happen. Everything depends on the size of the asteroid. So if you’re talking about something that has a kilometre in diameter then that would have global consequences.”

Wilks: “What are we doing about it?”

Khan: “You can do two things about it. The first thing you should always do is to understand how big the problem is and try to track, understand your enemy basically. So we should, and we do, track asteroids. We have telescopes staring into the sky for that purpose and when they see something that looks like an asteroid – so it’s moving – then the data is gathered from all of these computers and it goes into a database and that database is kept up to date, so we know where it is now, where it will be in a century from now. But there are limits to that. We cannot observe the smaller ones. So the smaller they get – because they’re dark, and then some of them come from the direction of the sun, like this one we’re talking about – the problem is you can’t observe them and there’s always a risk that you cannot mitigate.”

Wilks: “Yes, because the Chelyabinsk one indeed came from the direction of the sun. We didn’t see it coming. There’s nothing we can do?”

Khan: “This is really a grey zone, and probably for some time there won’t be anything we can do. Perhaps 50 years from now there will be.”

Wilks: “What would that be?”

Khan: “We might have telescopes positioned in orbit, orbiting the sun, and at different positions, and they would be able to observe. So we would have different telescopes looking at the same region of the sky and then we would see objects, or we could have radar scouring the interplanetary space, and detecting even smaller objects, like 10 metres in diameter or smaller.”